Phosphates & Corrosion Inhibitors
Sodium Hexametaphosphate (SHMP)
CAS 10124-56-8 — Scale Inhibitor & Sequestrant
SHMP is a versatile sequestrant and scale inhibitor for water treatment, food processing, and oilfield applications. Texas-Chem supplies industrial and food-grade SHMP in bulk drums, totes, and super sacks.
CAS Number
10124-56-8
Formula
(NaPO₃)₆
pH (1% solution)
6.5–7.5
Pack Sizes
Bags · Super Sacks · Bulk
Structure
(NaPO₃)₆ — Sodium Hexametaphosphate — CAS 10124-56-8
Safety & Regulatory
- NFPA Health
- 1 — Slight hazard
- NFPA Flammability
- 0 — Non-flammable
- NFPA Reactivity
- 0 — Stable
- OSHA PEL (dust)
- 5 mg/m³
- DOT Hazard Class
- Not regulated
- Skin/Eye
- Mild irritant
Grades & Packaging
Available Grades
Pack Sizes
Also Known As
Physical & Chemical Properties
| CAS Number | 10124-56-8 |
| Molecular Formula | (NaPO₃)₆ |
| Molecular Weight | 611.77 g/mol |
| Appearance | White granular powder |
| Solubility in Water | Highly soluble — >60 g/100 mL |
| pH (1% solution) | 6.5–7.5 |
| Phosphorus Content | ~69% as P₂O₅ |
| Iron Sequestration | Excellent — Fe²⁺ and Fe³⁺ |
| Calcium Sequestration | Good — 12 mg CaCO₃/g |
| Hygroscopicity | High — store in sealed containers |
| Grades Available | Industrial / Food Grade (FCC) |
| Hydrolysis | Slowly hydrolyzes to orthophosphate in hot water |
Industrial Applications
Water Treatment
SHMP is widely used as a sequestrant and scale inhibitor in municipal water treatment, cooling water systems, and oilfield water injection systems. Its near-neutral pH makes it compatible with a wide range of water treatment programs.
Food & Beverage
Food-grade SHMP is used as a sequestrant, emulsifier, and texturizer in processed cheese, seafood, beverages, and canned foods. It sequesters metal ions that cause rancidity and color changes.
Oil & Gas
Used in oilfield water treatment to prevent scale in injection wells, pipelines, and production equipment in the Permian Basin and Gulf Coast. Effective against calcium carbonate, calcium sulfate, and iron scale.
Detergent & Cleaning
Used as a builder and sequestrant in industrial and institutional cleaning formulations, sequestering calcium, magnesium, and iron ions that reduce cleaning effectiveness.
Textile Processing
SHMP is used as a sequestrant in textile dyeing and finishing to prevent metal ion interference with dyes and finishing chemicals.
Paper Manufacturing
Used as a dispersant and sequestrant in paper manufacturing to prevent scale in process water systems and improve pigment dispersion.
Why Source SHMP from Texas-Chem
- Industrial and food-grade SHMP in stock — drums, totes, and super sacks
- Consistent quality with CoA on every lot
- Same-week delivery across Texas; nationwide LTL
- Technical support for water treatment, oilfield, and food applications
- One rep from first call to final delivery
SHMP — Frequently Asked Questions
What is the difference between SHMP and STPP for water treatment?▾
SHMP (sodium hexametaphosphate) operates at near-neutral pH (6.5–7.5) and provides excellent iron sequestration in addition to calcium and magnesium. STPP (sodium tripolyphosphate) operates at higher pH (9.5–10.0) and is preferred for alkaline detergent and boiler water applications. SHMP is preferred for municipal water treatment and oilfield applications where near-neutral pH is required.
Is food-grade SHMP available?▾
Yes. Texas-Chem supplies food-grade SHMP meeting FCC (Food Chemicals Codex) specifications for use in seafood processing, processed cheese, and beverage applications. Food-grade SHMP is listed as GRAS by the FDA and approved as food additive E452 in the EU.
How should SHMP be stored?▾
SHMP is highly hygroscopic and must be stored in sealed containers in a dry location. Exposure to moisture causes rapid caking and hydrolysis to orthophosphate. Store in original sealed packaging away from heat and moisture. Shelf life is 1–2 years in sealed original packaging.
What is the typical treat rate for SHMP in cooling water?▾
SHMP is typically used at 2–10 ppm as a threshold scale inhibitor in cooling water systems. At these low concentrations, SHMP prevents scale nucleation and crystal growth without fully sequestering all hardness ions. Contact Texas-Chem at 855-TEX-CHEM for cooling water treatment program guidance.